Employees’ pension insurance

Hi all, I need someone to answer my question.
I checked my monthly slip and found out that they always take more than 15000 yen my salary as@ŒϊΆ”N‹ΰ•ΫŒ― Employees' pension insurance. Plus the Š“ΎΕ...and some other things I do not remember.
This is may be weird but I want to know , do I have the choice to ask them not to take theŒϊΆ”N‹ΰ•ΫŒ― Employees' pension insurance or it is decided by the law that is must be taken from the salary of everyone working in Japan.
Also, in Japan, if I quit my job, will I get paid for the period in which I am not having a job (for six months for example).
thank you

Employers have the obligations (when they employ over a certain number of employees) to have their "kousei nenkin" scheme, so as long as you are an employee, you are part of it. But if you plan to leave Japan (for good) after working some years, there is a system to get some of it back in a lumpsum after leaving.

The second question relates to unemployment insurance - if the company has enrolled you into that insurance, you should be able to, though if you quit of your own will, there will be a waiting period.

For pension scheme, you are automatically enrolled if the company are doing thing by the book.

If you paid into the unemployment insurance and also worker accident insurance, once you are out of job , fired or contract end not renew, you need to visit nearest Hello Work to apply for it and claim your benefit immediately.
If you quit on your own accord, you need to wait at least 1-3 month before apply/claim the benefit.
Payment varies depend on your salary, maybe..
https://en.m.wikipedia.org/wiki/Unemployment_insurance_(Japan)

if you escape from ŒϊΆ”N‹ΰiŒ’N•ΫŒ―),
you have to join ‘–―”N‹ΰ and ‘–―Œ’N•ΫŒ―. generally, the former is more cheaper than the latter, because your company contributes the same amount to the insurance and pension in the former case.